Selector switch



'April 3, 1945- l H. T. STENHAMMER 2,372,801

SELECTOR SWITCH Filed June l5, 1943 2 Sheets-Sheet l O O D 0 O O O OOO A0000 INVENTOR l ar'oZcZ'Senhcanmer Mam?? AT ORNE-SYS Ap 3, 1945. H. T. srl-:NHAMMER SELECTOR SWITCH 2 Sheets-Sheet 2 FledJunu 15. 1943 who. wm.

INVENoR Hu? 'olaz TStehammer- BY h l 4? Y A NEYS Patented Apr. 3, 1945 SELECTORSWITCH Harold T. Stenhammer, New York, N. Y., assignor to Control Instrument Company, Inc., Brooklyn, N. Y., a corporation of New York Application June 15, 1943, Serial No. 490,843

6 Claims.

This invention relates to improvements in telephone machine switching apparatus and has particular reference to a selector switch.

More especially, the switch of the present invention is of the type, also known as a connector, wherein a wiper shaft has both endwise and rotary motions produced by impulses transmitted t the switch in accordance with digits of a called line. The wiper shaft of this well-known type of switch has been commonly provided with vertical and rotary ratchet teeth by means of which the shaft is first stepped vertically and then rotated by the successive operations of stepping magnets, and, generally speaking, this equipment is of expensive and complicated construction.

An object of the present invention is to provide an improved switch of the two-motion type referred to which is of simple and practical construction and economical to manufacture, and which is positive .in its operation.

Another and more specic object is to operate the wiper shaft through its endwise or vertical movement independently of and relative to a ratchet, or its equivalent, which is utilized to impart rotary movement to said shaft, and to provide a driving connection between'sa-id ratchet and shaft which, at the conclusion of the vertical movement of the latter, will be controlled by the movement of said ratchet to rotate said shaft.

A further object is to utilize, in an improved manner, the initial vertical movement of the wiper shaft, which is independent of the rotatable ratchet, to reverse the position of one set of control contacts, and to similarly reverse another set of such contacts by a means actuated by the initial movement of said ratchet.

The inventive idea involved is capable of receiving a variety of mechanical expressions one of which is shown in the accompanying drawings; but it is to be expressly understood that saidv drawings are utilized merely for the purpose of describing the invention as a whole and not to denne the limits thereof, reference being had to the appended claims for this purpose.

In the drawingsn Fig. 1 is a side elevation, partly broken away and shown in section, of a selector switch constructed in accordance with the invention.

Fig. 2 is a similar view taken at right angles to Fig. 1,

Fig. 3 is a top plan view.

Fig. 4 is a vertical section taken substantially on the line 4 5. of Fig. 3. and

Fig. 5 is a fragmentary elevation, partly in secplate II.

tion, showing details of the mounting of the rotary stepping magnet on the wiper shaft.

In its preferred form, the switch is shown as comprising a supporting frame l0 of U-shape and having its upper and lower plates il and I2 connected by tie rods i3. Depending from the lower plate I2 is a terminal bank i4 which may be arcuate vor circular and which has vertical and horizontal rows of contacts l5 and I6 adapted to be engaged by the wipers l'I carried by the lower end of the wiper shaft I3. Said shaft extends through and has bearings in the plates II and I2 of the supporting frame so as to have vertical and rotary movements therein, and in an intermediate portion of the shaft the same is provided with the usual vertical ratchet teeth i9. Secured to and depending from the under surface of the upper plate il is the vertical stepping magnet 20 operated, in any suitable circuit in response to a series of impulses, to attract and release its armature 2l and thereby actuate the stepping pawl 22 to move the shaft I8 upwardly, from its normal position, one step for each energization of said magnet. A holding pawl 23 pre vents the return of the shaft by having its lower end yieldably held in engagement with the teeth I9 by a coil spring 2t connected to the upper end of said pawl, which latter end projects through As shaft I8 is moved vertically in response to the operation of magnet 20, wipers I1 move likewise with respect to the Vertical rows of terminals l5 until the impulses which operate said magnet cease, whereupon the wipers are then associated with horizontal rows I5 in which a set of terminals individual to a called line is to be found, said terminals being engaged by the wipers in response to the next series of impulses transmitted to the switch.

The upward movement of the shaft i3 is also utilized to control a set of spring contacts, generally indicated by numeral 25 and mounted on the upper plate II for the purpose of accomplishing certain well-known switching operations which need not be described in detail herein. These contacts have both normal and off-normal positions and are retained in the former position, during the'idle periods of the switch, by an arm 26 secured to the shaft I8 at the upper end thereof, the free end of said arm engaging and depressing a pin 2l carried by one of said spring contacts 25, as shown in Figs. l and 2. Iowever, upon the initial upward movement of the shaft I8, said arm 2B is raised, as indicated in dotted lines in Fig. 1, and disengaged from the pin 21, and said spring contacts thereupon assume their ofi-normal or closed positions and remain so until the shaft I8 is restored to normal.

The rotary movement of the, shaft I8 and its wipers is accomplished through the medium of a disc ratchet 28 mounted on the upper frame plate I I and having its axis of rotation coincident with that of said shaft which passes loosely through said ratchet so that the Vertical or end-Wise movement of the shaft is entirely independent of and relative to the ratchet, and the latter remains stationary during said vertical movement. In order to retain the ratchet against any possibilty of vertical movement during a similar motion of the shaft I8, said ratchet is provided with a depending sleeve 28 (Fig. 5) having an annular groove 29' in which is engaged a bifurcated end 30' of a holding block 3 I' secured to the upper surface of the plate Il. The step-by-step rotation of the ratchet 28, which occurs at the termi-` nation of the vertical movement of shaft I8. is under control of the rotary stepping magnet 29 which is responsive to impulses in the energizing circuit thereof to attract and release its armature 30. Pivoted to said armature, at 3l, is a spring-controlled stepping pawl 32 engageable, upon each attraction of said armature, with a tooth of saidratchet 28 to rotate it one step, there being a fixed cam 33 arranged in the path of said pawl, as the latter is advanced, to direct said pawl inwardly to thereby preventl any possible overthrow movement thereof, and consequently of said ratchet.. A spring-controlled holding pawl 34 is pivoted to the frame plate I I and engages the teeth of the ratchet to prevent return movement of the latter under the influence of its retractile spring 35 until the switch is ready to be restored to its normal condition. As the ratchet is stepped, the tooth of the pawl 3'4 rides overthose of the ratchet and the free end of said pawl, when the high points of said teeth are engaged, enters a recess 3B .of the advancing stepping pawl 32 so as to permit free movement of said holding pawl as it rides over said teeth and also prevent it from contacting the surface 49 of the pawl 32 and thereby disengaging the latter from the engaged tooth of said ratchet as said pawl 32 is being advanced.

The stepping of the ratchet 28 accomplishes the rotation of the shaft I8 and its wipers by a driving connection between said ratchet and shaft which, as shown, comprises a rod 31 extending upwardly from said ratchet adjacent its periphery and projecting through an opening 38 inthe arm 26, the latter having a free sliding contact on said rod during the vertical movement of the shaft. However, when the ratchet is rotated through its step-by-step movement, or is returned to normal by its retractile springs 35, as will later appear, its rod 3l will cause the arm 25, andconsequently the shaft I8, to rotate in one direction until the wipers I1 are properly positioned in accordance with the series of impulsestransmitted to the rotary stepping magnet` 29, or in the other direction under the iniluence of said spring 35.

The operation ofthe ratchet 28 is also utilized to control a set of spring contacts 39 mounted upon the upper Iplate I I and having normal and off-normal positions similar to the set of contacts 25. This control is attained by means of a rotatable member such as a cam 48 secured, by fastening screws 4I, to the under side of the ratchet 28 with the periphery ofthe cam extending outwardly beyond that'of said ratchet. Said cam is provided in its edge with a cam recess 42 which,

in the -normal position of the ratchet, receives a small roller 43 carried by a bracket 44 secured to the4 spring contact 45. In said normal position, the contact 45 and its associated contact 46, together with other contacts of the set 39, are closed while other groups of contacts of said set are opened. However, upon the first rotary movement of the ratchet 28, the cam 48 forces the roller 43 out of the recess 42 onto the high surface of the cam and, in so doing, reverses the positions of the contact groups in said set 39, to accomplish certain well-known functions, and they remain in such position until the ratchet and cam are restored to normal.

The release of the switch and restoration of its Darts to normal occurs as follows. The rotary release magnet 46 is first energized and, in attracting its armature 4l, causes an extension 48 on theY latter to engage the adjacent end of the holding pawl 34 to rock the same about its pivot and thus disengage the tooth of said pawl from the ratchet. As said pawl is so operated, its end adjacent the stepping pawl 32 contacts the surface 49 of the latter pawl, since this pawl is not now advanced, and swings the same away from the teeth of the ratchet. With both pawls thus disengaged from said ratchet, the retractile spring 35 rotates the ratchet and its cam 48 counterclockwise, asviewed in Fig. 3, until a projection 50 on the under side of the cam engages a stop 5| on the plate II, whereupon the ratchet is stopped in its normal yposition and the roller 43 is again engaged in the cam recess 42 to permit the switch contacts 39 to restore to normal. During the restoration of the ratchet, its rod 3l also rotates the wiper shaft I8 through the medium of the arm 2liv and when said rotative movement has ceased the closure of the spring contacts 45, 46 of the set 39 is utilized, in any manner wellknown in the art, to establish an operating circuit for the vertical release magnet 53 so that its armature 54 is attracted.

The operation of the release magnet eiects the disengagement of the vertical holding pawl 23 from the teeth I9 of the shaft I8 and also removes the stepping @pawl 22 to an inoperative position relative to said teeth, thereby permitting a free downward movement of said shaft to its` normal or starting position. To accomplish these ends, an arm 55 on the armature 54 extends inwardly over the plate II and at its inner bent end 55 contacts the upper end of the holding pawl 23 so that upon attraction of said armature, the arm 55 rocks said Ipawl to disengage its lower end from the teeth I9. At the same time, said arm also depresses one end of an angular lever 55 fulcrumed in an opening in the plate I l, the other end of said lever extending downwardly through said plate with the lower extremity of said other end engaging a pin 5'! projecting from the stepping pawl 22. Thus, when the upper end of said lever, which is bent around the end 55', is depressed and thereby rocked about its fulcrum by the arm 55, said lower end will swing the vertical stepping pawl out of operative association with the teeth I 9 and the shaft I8 will then be free to drop to its normal position. When reaching said position, the free end of the arm 25 again enages and depresses the pin 2l to restore the contacts 25 to normal and the switch is again in position for another operation, the circuits (not shown) for the release magnets 46 and 53 being broken by the opening of contacts of the sets 39 and 25, respectively.

What is claimed is:

1. In a selector switch, a vertically movable and rotatable wiper shaft, means to move said shaft vertically, means to rotate said shaft including a rotatable member with respect to which said shaft has independent vertical movement, a driving connection between said shaft and rotatable member to rotate the former in unison with said member in response to said rotating means, two sets of spring contacts having normal and offnormal positions, means on said shaft forming a part of said driving connection for retaining one set of said contacts in normal position until said shaft is moved vertically, and means on said ro tatable member to reverse the positions of the second set of contacts upon initial rotary movement of said member.

2. In a selector switch, a vertically movable and rotatable wiper shaft, means to move said shaft vertically, means to rotate said shaft including a ratchet through which said shaft extends for independent vertical movement rela tive thereto, a rod carried by said ratchet, an arm on said shaft having linear movement on said rod during the vertical movement of said shaft, said rod and arm thereafter combining to rotate said shaft in response to said rotating means, two sets of spring contacts each having normal and off-normal positions, one of said sets being retained in normal position by said arm prior to the initial vertical movement of said shaft, and means movable with. said ratchet for switching the second set of contacts from normal to off-normal position upon initial movement of said ratchet.

3. In a selector switch, a vertically movable and rotatable wiper shaft, means to move said shaft vertically, means to rotate said shaft including a ratchet through which said shaft extends for independent vertical movement relative thereto, a rod carried by said ratchet, an arm on said shaft having linear movement on said rod during the vertical movement of said shaft, said rod and arm thereafter combining to rotate said shaft in response to said rotating means, two sets of spring contacts each having normal and off-normal positions, one of said sets being retained in normal position by said arm prior to the initial vertical movement of said shaft, and a cam carried by said ratchet to shift the second set of spring contacts from normal t0 off-normal position when said ratchet is initially operated.

4. In a selector switch, a vertically movable and rotatable wiper shaft, means to move said shaft vertically, means to rotate said shaft including a rotatable member with respect to which said shaft has independent vertical movement, a driving connection between said shaft and rotatable member to rotate the former in unison with said member in response to said rotating means, a set of spring contacts having normal and offnormal positions, and means carried by said ratchet for shifting said contacts from normal to off-normal position upon initial operation of said rotating means.

5. In a selector switch, a Yvertically movable and rotatable wiper shaft, a ratchet loose on said shaft and having a driving connection therewith for rotating the same, means to move said shaft vertically relative to said ratchet, an electromagnetically operated stepping pawl for said ratchet, a holding pawl engageable with said ratchet, and ratchet releasing means for operating said holding pawl to disengage the same from said ratchet and to engage it with said stepping pawl to render the latter inoperative during the release of said ratchet.

6. In a selector switch, a vertically movable and rotatable wiper shaft, an electromagnetically operated stepping pawl engageable with Said shaft to move the same vertically, a holding pawl also engageable with said shaft to retain the same in raised position, means including a ratchet through which said shaft has independent vertical movement for rotating said shaft at the termination of the latter movement, a Vertical release magnet, a lever operable for rendering said stepping pawl inoperative during the vertical release of said shaft, and an extension on the armature of said release magnet for simultaneously releasing said holding pawl and operating said lever.

HAROLD T. STENHAMMER. 

